ABSTRACT Approximately 700,000 people in the United States have been diagnosed with a primary brain tumor. Of these, malignant gliomas (MGs) account for approximately 40% of all intracranial tumors, with an overall patient survival rate of only ~34%. More than any other cancer, brain cancer has lasting physical, cognitive, and psychological impacts on a patient?s life, and the highest per-patient initial cost of care. Surgical resection remains the cornerstone of therapy and the extent of resection correlates with patient survival. A limiting factor for resection, however, is the surgeon?s ability to differentiate the tumor from normal tissue. In pursuit of intraoperative guidance for the safe and maximal resection, fluorescence-guided surgery has emerged as an advanced adjunctive technique. The uses of surgical operative microscopes with FDA-approved fluorescein dye have shown significantly higher tumor resection rates (75-100%) in MGs than conventional surgeries (30-55%). However, most clinical-grade fluorescence microscopes (e.g., PENTERO 900 microscope with YELLOW 560? fluorescein module, Carl Zeiss Meditec AG) are hampered by high costs (~$330K), limited portability (~800 lbs), and lack of operation flexibility. Many surgeons prefer, and continue to use wearable surgical eye loupes, which allow for convenient and fast operation, but are not capable of fluorescence visualization. To overcome limitations of currently available surgical imaging techniques, we have preliminarily demonstrated safety and feasibility of an innovative wearable fluorescence prototype that piggybacks on eye loupes for identifying MGs (Pending Patent: PCT/US2018/41418). In this Phase-I study, we will collaborate with a startup company (Bioptics Technology, LLC) to miniaturize, optimize, and validate this low-cost device (~$8K) with user experience (e.g., ease of wearing, alignment, and operation) for easy and accurate fluorescent identification of MGs during resection. Compact LEDs and a small CMOS camera with dedicated optical filters will be optically integrated into different functional modules for florescence excitation and detection. These lightweight, compact, and inexpensive modules will be attached to the eye loupes to form an integrated wearable device, allowing for real-time ocular observation and video recording of fluorescence and color images. The device operating system will be optimized to be ?up and running? so that neurosurgeons can easily use it without much specialized training. To ensure appropriate performance and sufficient accuracy, this device will be first optimized and calibrated using tumor-simulating phantoms against the PENTERO 900 microscope with YELLOW 560? (Aim 1), and then validated in patients with MGs against histopathological analyses of biopsied samples taken from the surgical tumor margin (Aim 2). The potential market size of this device would be tens of millions of dollars in the US alone, providing a significant opportunity for commercialization. Ultimately, this affordable, wearable, and ergonomic device will significantly increase the ability of more surgeons to conduct fast and thorough operations, and thus improve surgical outcomes and reduce the burden on healthcare systems.